57 resultados para 398


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Cooling and sinking of dense saline water in the Norwegian–Greenland Sea is essential for the formation of North Atlantic Deep Water. The convection in the Norwegian–Greenland Sea allows for a northward flow of warm surface water and southward transport of cold saline water. This circulation system is highly sensitive to climate change and has been shown to operate in different modes. In ice cores the last glacial period is characterized by millennial-scale Dansgaard–Oeschger (D–O) events of warm interstadials and cold stadials. Similar millennial-scale variability (linked to D–O events) is evident from oceanic cores, suggesting a strong coupling of the atmospheric and oceanic circulations system. Particularly long-lasting cold stadials correlate with North Atlantic Heinrich events, where icebergs released from the continents caused a spread of meltwater over the northern North Atlantic and Nordic seas. The meltwater layer is believed to have caused a stop or near-stop in the deep convection, leading to cold climate. The spreading of meltwater and changes in oceanic circulation have a large influence on the carbon exchange between atmosphere and the deep ocean and lead to profound changes in the 14C activity of the surface ocean. Here we demonstrate marine 14C reservoir ages (R) of up to c. 2000 years for Heinrich event H4. Our R estimates are based on a new method for age model construction using identified tephra layers and tie-points based on abrupt interstadial warmings.

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In this study, evidence is provided of social immunity in the offspring of a sub-social species, the burying beetle, Nicrophorus vespilloides. Nicrophorus vespilloides is a carrion breeder and, in a similar fashion to the adult beetles, the offspring produce exudates that exhibit lytic activity, which are used to coat the breeding resource. This strategy defends against the microbial community. The lytic activity in larval exudates declines as the brood develops, perhaps being most beneficial at the start of the breeding bout. Changing levels of parental care through widowing/orphaning affects lytic activity in the larval exudates, with levels decreasing in the absence of both parents.

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The use of Raman and anti-stokes Raman spectroscopy to investigate the effect of exposure to high power laser radiation on the crystalline phases of TiO2 has been investigated. Measurement of the changes, over several time integrals, in the Raman and anti-stokes Raman of TiO2 spectra with exposure to laser radiation is reported. Raman and anti-stokes Raman provide detail on both the structure and the kinetic process of changes in crystalline phases in the titania material. The effect of laser exposure resulted in the generation of increasing amounts of the rutile crystalline phase from the anatase crystalline phase during exposure. The Raman spectra displayed bands at 144 cm-1 (A1g), 197 cm-1 (Eg), 398 cm-1 (B1g), 515 cm-1 (A1g), and 640 cm-1 (Eg) assigned to anatase which were replaced by bands at 143 cm-1 (B1g), 235 cm-1 (2 phonon process), 448 cm-1 (Eg) and 612 cm-1 (A1g) which were assigned to rutile. This indicated that laser irradiation of TiO2 changes the crystalline phase from anatase to rutile. Raman and anti-stokes Raman are highly sensitive to the crystalline forms of TiO2 and allow characterisation of the effect of laser irradiation upon TiO2. This technique would also be applicable as an in situ method for monitoring changes during the laser irradiation process

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Quantum yields of the photocatalytic degradation of methyl orange under controlled periodic illumination (CPI) have been modelled using existing models. A modified Langmuir-Hinshelwood (L-H) rate equation was used to predict the degradation reaction rates of methyl orange at various duty cycles and a simple photocatalytic model was applied in modelling quantum yield enhancement of the photocatalytic process due to the CPI effect. A good agreement between the modelled and experimental data was observed for quantum yield modelling. The modified L-H model, however, did not accurately predict the photocatalytic decomposition of the dye under periodic illumination.

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Scholars have devoted much attention to the causes and consequences of Presbyterian emigration from Ulster to the thirteen colonies before 1776. This article moves beyond the eighteenth century to examine the continued religious links between Presbyterians in Ireland and the United States in the nineteenth century. It begins with an examination of the influence of evangelicalism on both sides of the Atlantic and how this promoted unity in denominational identity, missionary activity to convert Catholics, and revivalist religion during the first half of the century. Though Irish Presbyterians had great affection for their American co-religionists, they were not uncritical, and significant tensions did develop over slavery. The article then examines the religious character of Scotch-Irish or Ulster-Scots identity in the late nineteenth century, which was articulated in response to the alleged demoralising influence of large-scale Irish immigration during and after the Famine of the 1840s, the so-called Romanisation of Catholicism, and the threat of Home Rule in Ireland. The importance of identity politics should not obscure religious developments, and the article ends with a consideration of the origins and character of fundamentalism, perhaps one of the most important cultural connections between Protestants in Northern Ireland and the United States in the twentieth century.

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The structure of the (2 X 1)CO-Pd(110) surface phase has been determined by LEED intensity analysis. The CO molecule is found to be adsorbed in an atop site, tilted by 11-degrees +/- 4-degrees with respect to the surface normal, with a C-O bond length of 1.16 +/- 0.04 angstrom. Interestingly, the C-O vibrational frequency for this system (2003 cm-1) is virtually identical to the frequency observed for the (2 X 1)CO-Ni(110) surface phase (1998 cm-1) which a previous LEED study has shown involves bridge bound CO molecules. The result indicates that care must be taken in assigning site symmetries on the basis of C-O stretching frequencies alone.

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The purpose of this article is to explore and illuminate teenagers' experiences of, and attitudes to, parades in Belfast. The research draws on responses from 125 teenagers located in interface areas (areas where Catholics and Protestants live side by side but apart) to government supported attempts to rebrand Orangefest (traditional parade associated with Protestant/Unionist/Loyalist community) and St Patrick's Day (traditional parade associated with Catholic/Nationalist/Republican community) as all-inclusive community events. For the most part, young people access these parades in pre-existing, single identity peer groups and view these parades as either inclusive or exclusive calling into question the extent to which Belfast's city centre can be viewed as shared space.

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Concern for crime victims has been a growing political issue in improving the legitimacy and success of the criminal justice system through the rhetoric of rights. Since the 1970s there have been numerous reforms and policy documents produced to enhance victims’ satisfaction in the criminal justice system. Both the Republic of Ireland and Northern Ireland have seen a sea-change in more recent years from a focus on services for victims to a greater emphasis on procedural rights. The purpose of this chapter is to chart these reforms against the backdrop of wider political and regional changes emanating from the European Union and the European Court of Human Rights, and to critically examine whether the position of crime victims has actually ameliorated.

While separated into two legal jurisdictions, the Republic of Ireland and Northern Ireland as common law countries have both grappled with similar challenges in improving crime victim satisfaction in adversarial criminal proceedings. This chapter begins by discussing the historical and theoretical concern for crime victims in the criminal justice system, and how this has changed in recent years. The rest of the chapter is split into two parts focusing on the Republic of Ireland and Northern Ireland. Both parts examine the provisions of services to victims, and the move towards more procedural rights for victims in terms of information, participation, protection and compensation. The chapter concludes by finding that despite being different legal jurisdictions, the Republic of Ireland and Northern Ireland have introduced many similar reforms for crime victims in recent years.

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OBJECTIVE:

To estimate the prevalence and distribution of open-angle glaucoma (OAG) in the United States by age, race/ethnicity, and gender.

METHODS:

Summary prevalence estimates of OAG were prepared separately for black, Hispanic, and white subjects in 5-year age intervals starting at 40 years. The estimated rates were based on a meta-analysis of recent population-based studies in the United States, Australia, and Europe. These rates were applied to 2000 US census data and to projected US population figures for 2020 to estimate the number of the US population with OAG.

RESULTS:

The overall prevalence of OAG in the US population 40 years and older is estimated to be 1.86% (95% confidence interval, 1.75%-1.96%), with 1.57 million white and 398 000 black persons affected. After applying race-, age-, and gender-specific rates to the US population as determined in the 2000 US census, we estimated that OAG affects 2.22 million US citizens. Owing to the rapidly aging population, the number with OAG will increase by 50% to 3.36 million in 2020. Black subjects had almost 3 times the age-adjusted prevalence of glaucoma than white subjects.

CONCLUSIONS:

Open-angle glaucoma affects more than 2 million individuals in the United States. Owing to the rapid aging of the US population, this number will increase to more than 3 million by 2020.